Azorella compacta infusion activates human immune cells and scavenges free radicals in vitro

Background: Azorella compacta is traditionally used in the form of tea (infusion), in the Andean region of South America, to treat various chronic diseases. However, the health-promoting properties of this herbal tea have not yet been extensively explored. Materials and Methods: The free radical scavenging activity of A. compacta infusion (ACI) was evaluated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and superoxide anion radical assays. The activation of immune cells by ACI, as determined by cell surface cluster of differentiation 69 expression, was measured by flow cytometry. The qualitative polyphenolic composition of ACI was investigated by HPLC/PDA/ESI-MS, (High-performance liquid chromatography coupled with photodiode array detection and electrospray ionization - mass spectrometry) and the total content of polyphenols was estimated by spectrophotometric methods. Results: Eight polyphenols including chlorogenic acid, 6,8-di-C-hexosyl apigenin, isoorientin, orientin, dicaffeoylquinic acid, biochanin A-O-glucoside, biochanin A-O-(malonyl)- glucoside, and licoisoflavone A were tentatively identified in ACI. The total contents of phenols, flavonoids, and tannins in lyophilized ACI were 5.40 mg/100 mg ACI, 1.79 mg/100 mg ACI, and 1.76 mg/100 mg ACI, respectively. ACI, within the range of 25-400 µg/mL, scavenged DPPH and O2 .– by 15-90% and 20-88%, respectively. The human natural killer (NK) cells were substantially activated by ACI, whereas T cells and granulocytes were slightly stimulated. Conclusion: Overall, the results demonstrate the free radical scavenging and immune-stimulating properties of ACI, and support, at least in part, its potential utilization as a functional herbal tea. for preventing chronic diseases and as a nonspecific immune stimulator during human immunosenescence.